This invention is directed to an apparatus and a method for determining an individual's preferred eye in a binocular situation where the preferred eye controls the visual pattern.
Research has shown that in a binocular situation where both eyes provide visual input, one eye controls the visual pattern. The controlling eye is the lead or preferred eye. Each individual also has a preferred ear, and a preferred hand. Alignment of these faculties has a significant effect on the ability of an individual to perform certain key activities such as reading. For example, good readers tend to be in perfect alignment or "sidedhess." They are either left-eye-left-handed or right-eye-right-handed. Conversely, poor readers tend to have a mixed "sidedness" (left-eye-right-handed or vice versa).
Research has also shown that "sidedness" is a prerequisite to learning visually, auditorially, and kinesthetically. A significant number of individuals with mixed eye-ear-hand preference experience learning difficulties, particularly in the area of reading. The majority of these individuals were changed to mixed "sidedness" because of cultural or ethnic superstitions. For example, Asian and Hispanic immigrants are most vulnerable to mixed "sidedness".
Accordingly, diagnostic techniques to detect learning problems must include "sidedness" as a factor. Further, parents and teachers must be reeducated regarding the importance of "sidedness" as it relates to the learning process. Thus, determining "sidedness" at an early age (5 to 7 years) will significantly impact the success of the learner. It is more advantageous to begin the learning process correctly than to remediate and attempt to reverse bad habits and practices.
However, determining eye preference has generally been limited to cases where an individual suffers from a visual atrophy unconnected to "sidedness." The case arises when one eye is defective and one eye is normal. Because the individual has to rely on the normal eye for proper vision, the normal eye is designated as the preferred eye. This designation, however, should not be mistaken with the case where both eyes are normal but the individual has simply developed a preference for one eye to control the visual pattern, namely the preferred eye.
The testing devices and procedures utilized in detecting visual atrophy in one eye are geared towards detection of a defective eye. They are not capable of efficient and accurate determination of eye preference in normal eyes.
The most relevant case in which a device designed for determining eye defects may possibly be used for determining eye preference in normal eyes, is in a case where the examining device is designed to detect blind spots in one eye. There, color slides are placed in front of each eye and the concept of fusion is used to determine the defective eye. If there is a lack of fusion, the preferred (i.e. normal) eye will be manifest through color response of the individual. In other words, if one eye is normal, the fused color will be tinted by the color entering the normal eye.
However, this approach is inefficient and inaccurate in determining eye preference when both eyes are normal. First, the approach relies on fusion which, in the case of normal eyes, will not reveal any detectable difference between the eyes. Second, the procedure is time consuming since several slides must be viewed in order to obtain reliable test results. Third, due to the complexity of the test, it must be administered by a trained professional at substantial cost.
Recently, the "differentiation" test has been utilized by optometrists to determine eye preference in normal eyes. However, this procedure requires the services of an optometrist at a substantial cost. Moreover, it takes approximately 50 minutes to administer the test.
Accordingly, there is a need for an eye examining device to determine eye preference in normal eyes in a short period of time. There is also a need for such a device to produce very accurate results in that short period of time. There is also a need for such a device to not require the services of an eye professional in its operation. There is also a need for such a device to be simple to use. There is also a need for such a device to be inexpensive.